Showing papers on "Chromium(III) oxide published in 2017"
TL;DR: Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.
Abstract: In this study, the preparation and electrochemical application of a chromium(III) oxide modified carbon paste electrode (Cr-CPE) and a screen printed electrode (SPE), made from the same material and optimized for the simple, cheap and sensitive simultaneous determination of zinc, cadmium, lead, copper and the detection of silver ions, is described. The limits of detection and quantification were 25 and 80 µg·L-1 for Zn(II), 3 and 10 µg·L-1 for Cd(II), 3 and 10 µg·L-1 for Pb(II), 3 and 10 µg·L-1 for Cu(II), and 3 and 10 µg·L-1 for Ag(I), respectively. Furthermore, this promising modification was transferred to the screen-printed electrode. The limits of detection for the simultaneous determination of zinc, cadmium, copper and lead on the screen printed electrodes were found to be 350 µg·L-1 for Zn(II), 25 µg·L-1 for Cd(II), 3 µg·L-1 for Pb(II) and 3 µg·L-1 for Cu(II). Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.
71 citations
TL;DR: In this paper, the effect of isovalent doping on the defect formation energies in Cr 2 O 3 is explored. And the authors show that Cr Frenkel and peroxide point defects are the most favourable defects in undoped Cr 3d and O 2p states.
8 citations
Patent•
18 Aug 2017
TL;DR: In this article, a method for preparing vanadium(III) oxide and chromium-III oxide by reduced vanadium-chromium precipitate is presented. But the method is not suitable for the extraction of hexavalent chromium residue.
Abstract: The invention discloses a method for preparing vanadium(III) oxide and chromium(III) oxide by reduced vanadium-chromium precipitate. The method comprises: slurrying reduced vanadium-chromium precipitate with water, adding a reducing agent, adjusting redox level of the system, and reducing V(IV) in the system into V(III); adding an alkali into the reduction system to carry out alkali leaching so that Cr(III) of the system is converted into Cr(OH)4-, carrying out solid-liquid separation to obtain chromium-bearing leachate and vanadium(III) oxide cake; drying the vanadium(III) oxide cake to obtain finished vanadium(III) oxide; adding an acid into the chromium-bearing leachate, and precipitating to obtain chromium oxide hydrate; calcining the chromium oxide hydrate to obtain calcined material; pickling the calcined material, and drying to obtain finished chromium(III) oxide. The method has the advantages that the usage of reducing agents is low, no toxic wastewater and residue containing hexavalent chromium are produced during production, the V content of the obtained vanadium(III) oxide is higher than 65.8%, the purity of chromium(III) oxide is higher than 98.2%, and vanadium-chromium recovery rate is high, with vanadium recovery rate higher than 99.1%, and chromium recovery rate higher than 96.1%.
1 citations
TL;DR: In this article, it was shown that the activity of catalysts prepared by mechanical mixing of aluminum oxide and the products from thermal decomposition of a carboxylate complex of chromium at 300-700 °C depends non-monotonically on the size of the chromium oxide crystallites in the range of 10-50 nm.
Abstract: It was established that the activity of catalysts prepared by mechanical mixing of aluminum oxide and the products from thermal decomposition of a carboxylate complex of chromium at 300-700 °C depends non-monotonically on the size of chromium oxide crystallites in the range of 10-50 nm. It was shown that the highest activity is achieved on catalysts in which the size of the chromium oxide crystallites is 23 nm.
1 citations
TL;DR: In this paper, a screen of likely binding groups showed that polyphosphonates were the most promising in terms of binding stability, and a better understanding of the binding mechanisms and adhesive tenacity of the trial polymers onto stainless steel was used.
1 citations